[11918] Let creatures evade when the enemy is unreachable

This commit is not great, but will be improved hopefully soon.
However it seems that it doesn't really cause problems, it is just not as good as it should be!

src/game/ThreatManager.cpp

@@ -252,7 +252,15 @@ HostileReference* ThreatContainer::addThreat(Unit* pVictim, float pThreat)
 void ThreatContainer::modifyThreatPercent(Unit *pVictim, int32 pPercent)
 {
     if(HostileReference* ref = getReferenceByTarget(pVictim))
-        ref->addThreatPercent(pPercent);
+    {
+        if(pPercent < -100)
+        {
+            ref->removeReference();
+            delete ref;
+        }
+        else
+            ref->addThreatPercent(pPercent);
+    }
 }
 
 //============================================================

src/game/Unit.cpp

@@ -8666,6 +8666,32 @@ bool Unit::SelectHostileTarget()
             SetInFront(target);
             if (oldTarget != target)
                 ((Creature*)this)->AI()->AttackStart(target);
+
+            // check if currently selected target is reachable
+            // NOTE: path alrteady generated from AttackStart()
+            if(!GetMotionMaster()->operator->()->IsReachable())
+            {
+                // remove all taunts
+                RemoveSpellsCausingAura(SPELL_AURA_MOD_TAUNT);
+
+                if(m_ThreatManager.getThreatList().size() < 2)
+                {
+                    // only one target in list, we have to evade after timer
+                    // TODO: make timer - inside Creature class
+                    ((Creature*)this)->AI()->EnterEvadeMode();
+                }
+                else
+                {
+                    // remove unreachable target from our threat list
+                    // next iteration we will select next possible target
+                    m_HostileRefManager.deleteReference(target);
+                    m_ThreatManager.modifyThreatPercent(target, -101);
+
+                    _removeAttacker(target);
+                }
+
+                return false;
+            }
         }
         return true;
     }

src/shared/revision_nr.h

@@ -1,4 +1,4 @@
 #ifndef __REVISION_NR_H__
 #define __REVISION_NR_H__
- #define REVISION_NR "11917"
+ #define REVISION_NR "11918"
 #endif // __REVISION_NR_H__